Nextcloud Server is a self hosted personal cloud system. After setting up a user or administrator defined external storage with fixed credentials, the API returns them and adds them into the frontend again, allowing to read them in plain text when an attacker already has access to an active session of a user. It is recommended that the Nextcloud Server is upgraded to 28.0.12, 29.0.9 or 30.0.2 and Nextcloud Enterprise Server is upgraded to 25.0.13.14, 26.0.13.10, 27.1.11.10, 28.0.12, 29.0.9 or 30.0.2.
Nextcloud server is a self hosted personal cloud system. In affected versions OAuth codes did not expire. When an attacker would get access to an authorization code they could authenticate at any time using the code. As of version 28.0.0 OAuth codes are invalidated after 10 minutes and will no longer be authenticated. To exploit this vulnerability an attacker would need to intercept an OAuth code from a user session. It is recommended that the Nextcloud Server is upgraded to 28.0.0. There are no known workarounds for this vulnerability.